java的公钥加密，私钥解密(非对称加密) V2，javav2,公钥加密，私钥解密(非对

java的公钥加密，私钥解密(非对称加密) V2，javav2,公钥加密，私钥解密(非对

公钥加密，私钥解密(非对称加密) V2

AsymmetricEncryption.java

package cn.itcast.gz;import java.io.ByteArrayOutputStream;import java.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;import java.io.ObjectInputStream;import java.io.ObjectOutputStream;import java.security.Key;import java.security.KeyPair;import java.security.KeyPairGenerator;import javax.crypto.Cipher;import javax.crypto.CipherInputStream;/** * 公钥加密，私钥解密(非对称加密) *  * @author long *  */public class AsymmetricEncryption {    public static void main(String[] args) throws Exception {        publicEnrypy();        privateEncode();    }    /**     * 加密的方法,使用公钥进行加密     * @throws Exception     */    public static void publicEnrypy() throws Exception {        Cipher cipher = Cipher.getInstance("RSA");        KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");        // 生成钥匙对        KeyPair keyPair = keyPairGenerator.generateKeyPair();        // 得到公钥        Key publicKey = keyPair.getPublic();        // 得到私钥        Key privateKey = keyPair.getPrivate();        // 设置为加密模式        cipher.init(Cipher.ENCRYPT_MODE, publicKey);        // 对数据进行加密        byte[] result = cipher.doFinal("aaa".getBytes());        //把私钥保存到硬盘上        saveKey(privateKey);        //把加密后的数据保存到硬盘上        saveData(result);    }    /**     * 解密的方法，使用私钥进行解密     * @throws Exception     */    public static void privateEncode() throws Exception {        Cipher cipher = Cipher.getInstance("RSA");        // 从硬盘中读取私钥        Key privateKey = loadKey();        //设置为解密模式，用私钥解密         cipher.init(Cipher.DECRYPT_MODE, privateKey);         FileInputStream fileInputStream = new FileInputStream(new File("E://data.data"));         CipherInputStream cipherInputStream = new CipherInputStream(fileInputStream, cipher);         ByteArrayOutputStream outputStream = new ByteArrayOutputStream();         byte[] buffer = new byte[1024];         int len = 0;         while ((len = cipherInputStream.read(buffer)) != -1) {             {                 outputStream.write(buffer, 0, len);             }             cipherInputStream.close();            System.out.println(outputStream.toString());         }        //cipherInputStream.        // 从硬盘中读取加密后的数据        //byte[] data = loadData();        //对加密后的数据进行解密，返回解密后的结果        //byte[] result = cipher.doFinal(data);        //System.out.println(new String(result));    }    /**     * 从硬盘中加载加密后的文件     * @return     * @throws FileNotFoundException     * @throws IOException     */    private static byte[] loadData() throws FileNotFoundException, IOException {        FileInputStream fileInputStream = new FileInputStream(new File(                "E://data.data"));        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();        byte[] buffer = new byte[1024];        int len = 0;        while ((len = fileInputStream.read(buffer)) != -1) {            outputStream.write(buffer, 0, len);        }        fileInputStream.close();        return outputStream.toByteArray();    }    /**     * 从硬盘中加载私钥     * @return     * @throws IOException     * @throws FileNotFoundException     * @throws ClassNotFoundException     */    private static Key loadKey() throws IOException, FileNotFoundException,            ClassNotFoundException {        ObjectInputStream inputStream = new ObjectInputStream(                new FileInputStream(new File("E://private_key")));        Key privateKey = (Key) inputStream.readObject();        return privateKey;    }    /**     * 把加密后的就过保存到硬盘上     * @param result     * @throws FileNotFoundException     * @throws IOException     */    private static void saveData(byte[] result) throws FileNotFoundException,            IOException {        FileOutputStream fileOutputStream = new FileOutputStream(new File(                "E://data.data"));        fileOutputStream.write(result);    }    /**     * 把私钥保存到硬盘上     * @param privateKey     * @throws IOException     * @throws FileNotFoundException     */    private static void saveKey(Key privateKey) throws IOException,            FileNotFoundException {        ObjectOutputStream outputStream = new ObjectOutputStream(                new FileOutputStream(new File("E://private_key")));        outputStream.writeObject(privateKey);    }}